The use of crossbows for hunting and target practice has increased in recent years. For some people, such as those who are elderly, disabled or young, using a traditional bow or a compound bow may be too physically strenuous. Therefore, crossbows offer these individuals an opportunity to hunt or shoot. For others, shooting with crossbows may offer variety over using only a traditional bow, or they may simply enjoy using a crossbow.
With this recent increase in the use of crossbows, there has also been a recent boom in the number and types of crossbow accessories that are being manufactured and sold. Typical crossbow users want to enjoy the benefits of as many of these accessories as they can, however, the crossbows of the prior art do not provide enough areas for users to mount all of their desired accessories to their crossbows because the crossbows of the prior art provide only limited mounting areas due to the configuration and operation thereof.
Currently, crossbows of the prior art allow for sighting devices, e.g., a scope or a sight, to be mounted on a sight bridge which is secured above, and extends slightly forward of, a trigger box of a firing assembly of the crossbow. The trigger box of prior art crossbows is provided at a rearward upper area of the crossbow. Due to the short length of the sight bridge and the typical size of the sighting device, no other accessories can logistically be mounted on the sight bridge. Crossbows of the prior art also allow for accessories, such as a forearm, a foregrip and/or a quiver, to be mounted to a lower surface of the crossbow forward of a finger pull mechanism of the firing assembly. Due to the limited space provided on the lower surface of the crossbow forward of the finger-pull mechanism, accessories other than a forearm, a foregrip and/or a quiver are not typically mounted in this area.
The remaining areas of the crossbow are not designed to have accessories mounted thereto because of the configuration and operation of the crossbow. For example, crossbows of the prior art do not have accessories mounted to a forward upper area thereof because the accessories would likely impede the operation of the crossbow by, for example, affecting the path of a bolt as it is fired from the crossbow, affecting the movement of the bowstring between a rearward cocked position and a forward rest position, affecting the movement of the limbs, affecting the movement of the power cables, or blocking the view of the sighting device.
It is also a desire to minimize a forward weight of crossbows. The forward weight of a crossbow is defined herein as a weight of the crossbow forward of a grip which is used to hold the crossbow while firing with the same hand. Similarly, a rearward weight of a crossbow is defined herein as a weight of the crossbow rearward of the grip. As the grip is where the crossbow is held, the position of the grip generally acts as a fulcrum point of the crossbow. The rearward weight of a crossbow is typically not hard for a user to support because a rear end of the crossbow is typically supported against a user's body when the crossbow is aimed and fired. However, the forward weight of the crossbow is not supported by anything and, therefore, the forward weight is the portion of the weight of the crossbow that is more likely to have a negative effect on a user's ability to support and hold steady the crossbow in a desired position for an extended period of time. Thus, it would be desirable to have a crossbow which has a center of gravity which is rearward of the grip or, at a minimum, be positioned only slightly forward of the grip.
Unfortunately, one of the inherent design setbacks with traditional crossbows is that these crossbows have centers of gravity which are positioned well forward of the grip as the riser, the limbs, and much of the barrel are positioned forward of the grip, such that they are included in the forward weight of the crossbows, thus making traditional crossbows excessively front-heavy. This is not desirable because a front-heavy crossbow will be harder for those utilizing the crossbow to aim and hold the crossbow in a steady position for an extended period of time, which may be necessary in order for the user to achieve an accurate shot, especially if the user is a hunter who may need to keep the crossbow in a ready position for an extended period of time while waiting for a target to approach.
It is also a desire to increase the strength of crossbows, e.g., to provide a crossbow that can hold an increased amount of energy compared to crossbows of the prior art. The amount of energy that a crossbow can hold is approximately equal to its draw length (the distance between the bowstring's position at rest and its position when cocked—also commonly referred to as a crossbow's power stroke) times its draw weight (the amount of force required to draw the crossbow, namely the amount of force required to move the bowstring from its rest position to its cocked position), divided by two. Thus, in order for crossbows to have increased strengths, the draw length and/or the draw weight must be increased.
In order to make crossbows more usable and ergonomic for a myriad of different sized individuals, it is not always desirable to increase the draw weight of the crossbow as an increase in draw weight will likely lead to a number of people having to struggle with the ability to cock the bowstring and ultimately with another number of people simply being unable to cock the bowstring at all. Thus, a more preferred manner of increasing the strength of a crossbow is achieved by increasing the draw length of the crossbow.
However, increasing the draw length of the crossbow has its own inherent disadvantages. In direct trigger crossbows (those where the firing assembly has the action, e.g., the string latch, in direct alignment with the finger-pull mechanism), an increase in the draw length of the crossbow necessarily means adding more weight to the forward weight of the crossbow and, furthermore, adding that weight distal to the fulcrum point, namely the grip, of the crossbow (as the finger-pull mechanism is always positioned slightly forward of the grip), thereby making this weight even harder to support than weight added proximate to the fulcrum point. By adding forward weight to the crossbow, the center of gravity of the crossbow also necessarily moves further forward of the grip. In order to combat the inherent front-heaviness of crossbows, various efforts exist in the prior art to try and solve this problem.
For instance, U.S. Pat. No. 7,677,233 to Bednar discloses a support rod which is pivotally connected to the crossbow forward of the grip to allow the user to support the forward weight of the crossbow while waiting for a target to approach. While such support rods do provide advantages, the use of such support rods can have their own disadvantages such that some users might prefer to not use them. For instance, the support rods may become cumbersome or impractical to use in the location where the user is shooting.
In another example, United States Patent Application Publication No. US 2011/0203561 to Shaffer et al. discloses a crossbow having limbs formed from carbon fiber, which was known in the prior art, but also has a riser formed from carbon fiber. The use of carbon fiber in both the limbs and the riser reduces the weight at the front of the crossbow. While forming the riser of a carbon fiber material would certainly lighten the overall weight of the crossbow, the resultant crossbow is still provided with substantial forward weight which must be supported by the user.
Another example is the creation of a reverse-draw crossbow Which moves the positioning of the riser and the limbs to proximate the grip. Reverse-draw crossbows thus typically do not have as much forward weight as traditional crossbows or, at a minimum, have a higher percentage of the forward weight thereof being positioned proximate to, rather than distal to, the grip. Thus, reverse-draw crossbows also inherently move the center of gravity closer to the grip, and possibly even rearward of the grip. Reverse-draw crossbows, however, typically aren't as powerful as traditional crossbows. While reverse-draw crossbows can be modified to make them as powerful as traditional crossbows, the reverse-draw crossbows then typically become big and bulky, which is undesirable.
In other examples, crossbow manufacturers have reduced the forward weight of crossbows by providing the crossbows with shortened barrels and/or by shortening the overall length of the crossbows by using bullpup stocks (those where the firing assembly has the action, e.g., the string latch, provided rearward of the finger-pull mechanism). Thus, each of these also necessarily have moved the center of gravity of the crossbow rearward or toward the user.
While shortened barrels aid in reducing the forward weight of the crossbows and thus aid in moving the center of gravity of the crossbows toward the user, crossbows with shortened barrels come with their own disadvantages. More specifically, shortened barrels generally cause the crossbow to have a reduced draw length which, as explained hereinabove, is undesirable as the crossbow will then not be able to hold as much energy as may be desired (unless the draw weight is increased). A reduction in energy of the crossbow has disadvantages as this reduction in energy may result in the crossbow not being able to cause a bolt fired therefrom to provide a humane quick kill of the target, but rather may only injure the target or cause a slow, inhumane kill of the target.
Bullpup stocks generally allow for a reduction in the overall length of the crossbow because the string latch is moved closer to the user. This movement of the string latch, and thus the necessary rearward movement of associated parts of the firing assembly, results in a reduction in the forward weight (and an increase in the rearward weight) of the crossbow. Therefore, the center of gravity of the crossbow is likewise moved rearward, i.e., toward the user, thereby making the crossbow easier for a user to aim and shoot. Bullpup stocks also achieve this desired effect while maintaining the same length of pull as in crossbows having a direct trigger.
Length of pull of a crossbow is defined as the distance between a finger-pull mechanism of a firing assembly and a rear portion of the crossbow that contacts a user's body, namely a butt end of all prior art crossbows. Crossbows of the prior art all typically have a length of pull of approximately fourteen (14) inches plus or minus one (1) inch. It has been found that a substantial population of typical crossbow users require a length of pull distance of approximately thirteen (13) to fifteen (15) inches to allow the user to comfortably position the butt end of the crossbow against a front of their bodies proximate to their shoulder and to use a hand to support the crossbow at the grip proximate the finger-pull mechanism with one of their fingers of that hand (typically their index finger) being in position to pull the finger-pull mechanism.
Crossbows of the prior art are either outfitted with a butt end that is fixed in position or a butt end that can be rearward extended from a base position. In the case of the former, the crossbow manufacturer determines the length of pull for that crossbow, with the understanding that that particular length of pull will not be ideal for all users, e.g., those who have shorter or longer arms than normal. In the case of the latter, the crossbow manufacturer further sets a minimum length of pull for that crossbow, but provides the crossbow with a telescoping butt member such that the length of pull for that crossbow can be increased as desired to within the limits of the telescoping butt member. Telescoping butt members typically allow for a user to add an additional three (3) to four (4) inches to the minimum length of pull of the crossbow. Padding or cushioning can also be added to the butt end which further increases the length of the crossbow.
Due to the typical lengths of pull of prior art crossbows, bullpup stocks typically provide a distance of two (2) to five (5) inches from the finger-pull mechanism to the string latch, with a maximum known distance of six (6) inches. The reason this distance is limited to six (6) inches is twofold. First, the sighting device is mounted on top of a trigger box which houses the string latch. If the string latch is moved even further rearward of the finger-pull mechanism, sufficient space is not provided for the user to position his/her eye against an eyepiece of the sighting device. Second, the position of the user's head/face could come into contact with the trigger box or the cocked bowstring (and its travel path when it is released from its cocked position).
Thus, in view of the foregoing, there remains a need for a crossbow which provides more areas for mounting of accessories compared to crossbows of the prior art, and which provides for greater draw length compared to crossbows of the prior art, and which provides for a crossbow having a forward weight which allows a user to support the crossbow at the grip for extended periods of time. The present invention provides such a crossbow.